@objc public protocol MyCollectionViewProtocol {
    func scrollViewShouldScrollToTop()
}

public class MyCollectionView: UICollectionView {
  weak var cvDelegate : MyCollectionViewProtocol?
  ... //rest of the code isnt related to this question in particular

open class RxMyCollectionViewDelegateProxy : DelegateProxy<MyCollectionView, MyCollectionViewProtocol>
    , DelegateProxyType
, MyCollectionViewProtocol {

    public static func currentDelegate(for object: MyCollectionView) -> MyCollectionViewProtocol? {
        return object.cvDelegate
    }

    public static func setCurrentDelegate(_ delegate: MyCollectionViewProtocol?, to object: MyCollectionView) {
        object.cvDelegate = delegate
    }


    public weak private(set) var collectionView: MyCollectionView?


    internal lazy var shouldScrollPublishSubject: PublishSubject<Void> = {
        let localSubject = PublishSubject<Void>()
        return localSubject
    }()

    public init(collectionView: ParentObject) {
        self.collectionView = collectionView
        super.init(parentObject: collectionView, delegateProxy: RxMyCollectionViewDelegateProxy.self)
    }

    // Register known implementations
    public static func registerKnownImplementations() {
        self.register { RxMyCollectionViewDelegateProxy(collectionView: $0) }
    }


    //implementation of MyCollectionViewProtocol
    public func scrollViewShouldScrollToTop() {
        shouldScrollPublishSubject.onNext(())
        self._forwardToDelegate?.scrollViewShouldScrollToTop()
    }

    deinit {
        shouldScrollPublishSubject.onCompleted()
    }
}

extension Reactive where Base: MyCollectionView {
    public var delegate: DelegateProxy<MyCollectionView, MyCollectionViewProtocol> {
        return RxMyCollectionViewDelegateProxy.proxy(for: base)
    }

    public var shouldScrollToTop: ControlEvent<Void> {
        let source = RxMyCollectionViewDelegateProxy.proxy(for: base).shouldScrollPublishSubject
        return ControlEvent(events: source)
    }
}

collectionView.rx.shouldScrollToTop.debug().subscribe(onNext: { (state) in
        print("I should scroll to top")
    }, onError: { (error) in
        print("errored out")
    }, onCompleted: {
        print("completed")
    }, onDisposed: {
        print("Disposed")
    }).disposed(by: disposeBag)